In the design of pool wall structures, several problems in particular are encountered. These all arise from the fact that in endeavouring to contain a large mass of water, a substantial hydraulic pressure is developed and applied against the surrounding wall. This pressure creates a spreading force which tends to stretch the pool wall and requires a pool wall support structure that provides a counteracting force to contain the water in the pool. Where the wall is composed of segmented portions, the force of the water tends to separate the pool wall segments from each other at their corners and cause corner spreading. Where the pool wall is not circular this pressure also differentially acts on pool wall segments with the tendency to reshape the walls into a circle. In cases where the pool wall segments are formed of flat panels supported at their ends by being joined to the corner of the next adjacent panel, the hydraulic pressure tends to cause bulging in the centre of the panel.
An additional problem encountered in constructing above ground pools having a pool-side walkway, deck or steps, is the expense and complication of supporting these structures.